A spacecraft with a mass of 5000kg is in circular orbit 2000km above the surface of mars. How much work must the spacecraft engines perform to move the spacecraft to a circular orbit that is 4000km above the surface? (hint Total Energy E, + E)

In deep space, sphere A of mass 30 kg is located at the origin of an x axis and sphere B of mass 10 kg is located on the axis at x = 0.85 m. Sphere B is released from rest while sphere A is held at the origin. (a) What is the gravitational potential energy of the two-sphere system just as B is released? (b) What is the kinetic energy of B when it has moved 0.25 m toward A? Additional Materials eBook Powers of Ten

The three spheres in the figure, with masses mA = 79 g, mB = 7 g, and mc = 22 g, have their centers on a common line, with L = 21 cm and d = 4 cm. You move sphere B along the line until its center-to-center separation from C is d = 4 cm. How much work is done on sphere B(a) by you and (b) by the net gravitational force on B due to spheres A and C? (a) Number i (b) Number i B Units Units C ✪ ✪

Loki is standing on top of the Avenger's Tower. If the tower is 72 m tall and Loki has a mass of 55 kg, what is Loki's potential energy at the top of the tower? Do NOT include units Use g = 9.8 m/s2 Round to the nearest whole number

How much work is required to stop an electron (m=9.11×10−31kg)(m=9.11×10−31kg) which is moving with a speed of 1.80×106 m/sm/s ?

While I can kick a soccer ball so that it has a speed of 10 m/s, David Beckham can kick a  ball so that it has a speed of 45 m/s. How many times greater is the Kinetic Energy of the ball kicked by Beckham than the ball kicked by me?

A couple of soccer balls of equal mass are kicked off the ground at the same speed but at different angles. Soccer ball A is kicked off at an angle slightly above the horizontal, whereas ball B is kicked slightly below the vertical. How do each of the following compare for ball A and ball B? (a) The initial kinetic energy and (b) the change in gravitational potential energy from the ground to the highest point? If the energy in part (a) differs from part (b), explain why there is a difference between the two energies.

Suppose that a spacecraft of mass 6.9 x 104 kg at rest in space fires its rockets to achieve a speed of 5.2 x 103 m/s. How much work has the fuel done on the spacecraft?

In deep space, sphere A of mass 93 kg is located at the origin of an x axis and sphere B of mass 140 kg is located on the axis at x = 7.2 m. Sphere B is released from rest while sphere A is held at the origin. (a) What is the gravitational potential energy of the two-sphere system just as B is released? (b) What is the kinetic energy of B when it has moved 3.8 m toward A? (a) Number i Units (b) Number i Units

A hiker of mass 73 kg is going to climb to the top of Mount Tam, which has an elevation of 2,574 ft. a) If the hiker starts climbing at an elevation of 545 ft, what will their change in gravitational potential energy be, in joules, once they reach the top? Assume the zero of gravitational potential energy is at sea level.  b) Repeat the above calculation for the change in gravitational potential energy, but assume the gravitational potential is zero at the top of the mountain.